Polymer or hydrogel-coated substrates are used in many technological applications. For example, polymer or hydrogel coated substrates are used for the preparation and/or analysis of biological molecules. Molecular analyses, such as certain nucleic acid sequencing methods, utilize the attachment of nucleic acid strands to a polymer or hydrogel-coated surface of a substrate. The sequences of the attached nucleic acid strands can then be determined by a number of different methods that are well known in the art.
Sequencing-by-synthesis (SBS) typically exploits the attachment of template DNA strands to a polymer-coated flowcell surface. An exemplary procedure for preparing the glass surface of a flowcell for SBS comprises: (1) functionalization of the surface with a reactive silane by chemical vapor deposition (CVD); (2) covalently attaching a preformed polyamide polymer to the flow cell surface by a thermal reaction; and (3) attaching sequencing primers to a reactive moiety of the polymer using crosslinking chemistry. After the surface is prepared, DNA is attached to the primers on the surface, amplified to generate clusters which are then sequenced-by-synthesis to read individual bases in the sequence. Every step of the preparation of the flow cell surface or coating is amenable to being performed in solution using microfluidics and therefore can be performed on-board the instrument. The deposition of the polymer layer can also be performed by spin or spray coating. One typical exception is the CVD of functionalized silane, which is performed in a high temperature vacuum oven.
Although it is known that a strong base can be used to efficiently remove the silane layer, this method would create the need for a CVD oven in order to renew the flow cell. The current state-of-the art is that after the sequencing is performed, the flow cell is not reused for sequencing and is instead disposed. No efficient way of renewing the flow cell are commercially available. Therefore, it would be desirable to design a sequencing process where the flow cell can be regenerated or recycled to reduce the cost associated with SBS.